FTBFS: "rpc/rpc.h" not found (removed from glibc 2.32)

[Simon Chopin]

Imported from Debian bug http://bugs.debian.org/992564:

Source: caml-crush
Severity: serious
Tags: upstream ftbfs

Dear Maintainer,

The package fails to build from source in clean environments as it
relies on "rpc/rpc.h" being present, while those headers have been
removed in glibc 2.32, considered obsolete. The solution is to use tirpc
instead.

There is a PR upstream to adapt the build system to use tirpc :

https://github.com/caml-pkcs11/caml-crush/pull/47

-- System Information:
Debian Release: 11.0
  APT prefers impish
  APT policy: (500, 'impish'), (50, 'impish-proposed')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.13.0-14-generic (SMP w/8 CPU threads)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled